3D Printed 18 GHz to 28 GHz Horn Antenna and Gradient Index of Refraction Lens

A 3D printed K-band horn antenna with a planar GRIN (gradient index of refraction) lens is reported. The horn antenna has elliptically flared sidewalls that are 3D printed using polylactic acid (PLA) and covered in copper tape. The planar GRIN lens models the phase delay profile of a spherical Luneburg lens, with a gain increase of 5 dB or better across the 18 GHz to 28 GHz band and is printed using ECO-ABS. By moving a dielectric cylinder with ε
r
= 2.4 on the inner surface of the lens, a beam-steering angle of ±5° is demonstrated.